Convert //content ObjC Instance Variable Names From Trailing to Leading Underscore

Clang-Tidy performed all of the transformations in this change.

BUG=1030028
[email protected]
Associated mechanical changes to header files.

Change-Id: I5453a6602efec4f4d26fc0fe88a9691dbdcf26de
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1961088
Reviewed-by: Robert Liao <[email protected]>
Reviewed-by: Elly Fong-Jones <[email protected]>
Commit-Queue: Robert Liao <[email protected]>
Cr-Commit-Position: refs/heads/master@{#723845}
diff --git a/content/shell/browser/shell_application_mac.mm b/content/shell/browser/shell_application_mac.mm
index 9266f387..92d3be7c 100644
--- a/content/shell/browser/shell_application_mac.mm
+++ b/content/shell/browser/shell_application_mac.mm
@@ -16,26 +16,26 @@
 
 @interface ShellCrApplication ()<NativeEventProcessor> {
   base::ObserverList<content::NativeEventProcessorObserver>::Unchecked
-      observers_;
+      _observers;
 }
 @end
 
 @implementation ShellCrApplication
 
 - (BOOL)isHandlingSendEvent {
-  return handlingSendEvent_;
+  return _handlingSendEvent;
 }
 
 - (void)sendEvent:(NSEvent*)event {
-  base::AutoReset<BOOL> scoper(&handlingSendEvent_, YES);
+  base::AutoReset<BOOL> scoper(&_handlingSendEvent, YES);
 
   content::ScopedNotifyNativeEventProcessorObserver scopedObserverNotifier(
-      &observers_, event);
+      &_observers, event);
   [super sendEvent:event];
 }
 
 - (void)setHandlingSendEvent:(BOOL)handlingSendEvent {
-  handlingSendEvent_ = handlingSendEvent;
+  _handlingSendEvent = handlingSendEvent;
 }
 
 - (IBAction)newDocument:(id)sender {
@@ -47,12 +47,12 @@
 
 - (void)addNativeEventProcessorObserver:
     (content::NativeEventProcessorObserver*)observer {
-  observers_.AddObserver(observer);
+  _observers.AddObserver(observer);
 }
 
 - (void)removeNativeEventProcessorObserver:
     (content::NativeEventProcessorObserver*)observer {
-  observers_.RemoveObserver(observer);
+  _observers.RemoveObserver(observer);
 }
 
 @end